Hi Avnish,
There are following datatypes supported by JSON format:
Type | Description |
Number |
double- precision floating-point format in JavaScript |
String |
double-quoted Unicode with backslash escaping |
Boolean |
true or false |
Array |
an ordered sequence of values |
Value |
it can be a string, a number, true or false, null etc |
Object |
an unordered collection of key:value pairs |
Whitespace |
can be used between any pair of tokens |
null |
empty |
Number
-
It is a double precision floating-point format in JavaScript and it depends on implementation.
-
Octal and hexadecimal formats are not used.
-
No NaN or Infinity is used in Number.
The following table shows number types:
Type | Description |
Integer |
Digits 1-9, 0 and positive or negative |
Fraction |
Fractions like .3, .9 |
Exponent |
Exponent like e, e+, e-,E, E+, E- |
SYNTAX:
var json-object-name = { string : number_value, .......}
EXAMPLE:
Example showing Number Datatype, value should not be quoted:
var obj = {marks: 97}
String
The table shows string types:
Type | Description |
" |
double quotation |
\ |
reverse solidus |
/ |
solidus |
b |
backspace |
f |
form feed |
n |
new line |
r |
carriage return |
t |
horizontal tab |
u |
four hexadecimal digits |
SYNTAX:
var json-object-name = { string : "string value", .......}
EXAMPLE:
Example showing String Datatype:
var obj = {name: 'Amit'}
Boolean
It includes true or false values.
SYNTAX:
var json-object-name = { string : true/false, .......}
EXAMPLE:
var obj = {name: 'Amit', marks: 97, distinction: true}
Array
-
It is an ordered collection of values.
-
These are enclosed square brackets which means that array begins with .[. and ends with .]..
-
The values are separated by ,(comma).
-
Array indexing can be started at 0 or 1.
-
Arrays should be used when the key names are sequential integers.
SYNTAX:
[ value, .......]
EXAMPLE:
Example showing array containing multiple objects:
{
"books": [
{ "language":"Java" , "edition":"second" },
{ "language":"C++" , "lastName":"fifth" },
{ "language":"C" , "lastName":"third" }
]
}
Object
-
It is an unordered set of name/value pairs.
-
Object are enclosed in curly braces that is it starts with '{' and ends with '}'.
-
Each name is followed by ':'(colon) and the name/value pairs are separated by , (comma).
-
The keys must be strings and should be different from each other.
-
Objects should be used when the key names are arbitrary strings
SYNTAX:
{ string : value, .......}
EXAMPLE:
Example showing Object:
{
"id": "011A",
"language": "JAVA",
"price": 500,
}
Whitespace
It can be inserted between any pair of tokens. It can be added to make code more readable. Example shows declaration with and without whitespace:
SYNTAX:
{string:" ",....}
EXAMPLE:
var i= " sachin";
var j = " saurav"
null
It means empty type.
SYNTAX:
null
EXAMPLE:
var i = null;
if(i==1)
{
document.write("<h1>value is 1</h1>");
}
else
{
document.write("<h1>value is null</h1>");
}
JSON Value
It includes:
SYNTAX:
String | Number | Object | Array | TRUE | FALSE | NULL
EXAMPLE:
var i =1;
var j = "sachin";
var k = null;